The trypsin inhibitor content of 61 wild edible plant foods of Niger

In the western Sahel and many other regions of sub-Saharan Africa, wild edi ble plants contribute significantly to human diets, not only during periods when cereal staples are scarce, but also when they are readily available. Although there have been published reports regarding the nutrient contents of these plant foods, little attention has been devoted to their content of antinutrients such as calcium chelators and inhibitors of the pancreas-der ived proteases, trypsin and chymotrypsin, which are required for the effici ent digestion and absorption of dietary proteins. In this study, aqueous ex tracts of 61 different leaves, seeds, fruits and flowers of edible plants g athered in the Republic of Niger were analyzed for their content of trypsin inhibitory substances using alpha -N-benzoyl-DL-arginine-p-nitroanilide as the substrate and bovine trypsin as the enzyme source. Twelve of these pla nt foods contained more antitrypsin activity than soybeans (1.34-8.18 vs. 1 .32 mug trypsin inhibited/mg dry weight). Boiling for 3 min did not inactiv ate the antitrypsin activity in most of the plant extracts. These data conf irm that more than half of the wild edible plant foods widely consumed by v arious populations who inhabit the western Sahel contain significant quanti ties of heat-stable trypsin inhibitor that could possibly compromise the bi oavailability of proteins present in the diets of these populations.